Question

A ladder is placed against a wall with an angle between the ladder and the ground of 76°. If the ladder must reach 10 m up the wall, how long does the ladder need to be?

Answer 1

i don't know where to start

Answer 2

Your start would be to make a diagram
of the right-angled triangle.

Then you should see that if L is the length of the ladder,
sin76° = 10/L
L = 10/sin76° = 10.306 m